The present invention relates to a hydrostatic continuously variable transmission which is used as an automotive transmission in various work vehicles, such as a tractor, a lawnmower, a combine harvester, a rice transplanter, and the like.
In hydrostatic continuously variable transmissions (HSTs), hydraulic fluid needs to be cooled since the hydraulic fluid is heated by friction. For example, as disclosed in JP No. 8-145168 A, charge fluid pumped from a charging pump is cooled through an oil cooler before being supplied into a charge fluid path.
Conventionally, the oil cooler is provided in a cooling air path in a radiator of an engine, and the oil cooler is connected to related devices via external pipes. A number of parts for connecting the pipes are required, and piping requires much labor.